Internal-combustion engine



Aug. 20, 1929.

G. s. DLN ET L INTERNAL COMBUSTION EBGIN 2 Sheets-Sheet l Filed July 19, 1927 2 Sheets-Shee'. 2`

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Hee for H Sfewaff Aug. 20, 1929.- G. s. EDLIN ET AL INTERNAL coMBUsTIoN ENGINE Filed July 19, 1927 FUE@ Patented Aug. 20, 1929.

UNITED STATES PATENT OFFICE. I

GEORGE STANLEY EDLIN AND HECTOR HAL-IEAD STEWART, OF HAMILTON, NEW ZEALAND.

INTERNAL-COMBUSTION ENGINE.

Application led July 19, 1927, Serial No, 206,918, and in New YZealand. July 24, 1926.

This invention relates tointernal combustion engines of the two stroke type, wherein the fuel charge is ignited between a piston and a sleeve closed at one end, and reciprocated in reverse direct-ions within a cylinder, the piston operating within the sleeve.

The object of the invention is to provide improvements in internal combustion engines of the above mentioned type, whereby friction of movin@` parts is reduced, greater stability of the engine and correct alignment of said moving parts are ensured, and main tained, besides which the engine is enabled to be produced in a more compactform than hitherto, and more complete scavenging is effected.

One feature of the invention consists in providing between the piston and the sliding sleeve, a fixed sleeve, the piston operating within the latter, and the sliding sleeve between the fixed sleeve and the engine cylinder, said fixed sleeve containing ports which correspond with exhaust ports in the cylinder.

Another feature of the invention consists in eliminating or dispensing with the ports usually provided in the sliding sleeve for the transfer of a fuel charge from the initial compression chamber into the space between the head of the sliding sleeve and the piston, said sliding sleeve being provided with ports approximately midway of its height which ports when the sleeve is on its up stroke register with the lower ends of transfer ports extending down through the cylinder wall, to a point just above the top of the fixed sleeve, and admit a charge of fuel to the space between the head of the sliding sleeve and the piston for further compression and ignition.

A further feature of the invention, consists in providing an induction port or ports, in the cylinder at a distance from the head thereof, so that as the sliding sleeve Amoves downwards a partial vacuum is created in the initial compression chamber and upon the head of the sliding sleeve clearing the induction port or ports, a charge is induced into said initial compression chamber to be compressed therein and finally transferred to between the head of the sliding` sleeve and the piston, upon the upward stroke of said sleeve.

The invention will be more fully described in conjunction with the accompanying drawings, wherein Figure 1 is a vertical sectional of the improved engine,

Figure 2 a part vertical taken at right angles to the section in Figure 1,

Figures 3 and 4 sectional plan views taken on the lines A-A or B-B respectively Figure 1, l

Figure 5 a sectional elevation and Figure 6 a sectional plan view of an alternative form of the fixed sleeve,

Figure 7 a part sectional elevation and Figure 8 a sectional plan view on the line C-C Figure 7, illustrating a further arrangement of ports.

The engine cylinder 1 which is preferably water aoketed in the usual manner, has working in right lines therein, a sleeve 2 closed at its end 2a remote from the crank shaft 4, and operated per medium of connecting rods 5 each passed at one end upon a pin 6 secured to the sleeve 2 and projecting therefrom, through slots 7 in the cylinder 1, the other ends of said connecting rods `5 being passed upon crank pins 8 located at corresponding points on the shaft It, and diametrically opposite a crank pin 9 from which a connecting rod 10 passes to a piston 11 operable within a 'stationary sleeve 12 and also interiorly of the sleeve 2 so that the latter and the piston 11 balance the shaft 4i and always move in opposite directions.

Near its closed end 2a the sleeve 2 contains one lor more radial ports 13 capable of being caused to register with one or more ports 14 in and near the top of the cylinder wall, whereby a charge of fuel mixture admitted to a chamber 16 on the cylinder through a non.

return valve at 15 is enabled to be transferred from said chamber 16 into the sleeve 2 between the closed end 2a thereof and the piston 11 which works in the' stationary sleeve l12.

At or near its open end the sleeve 2 contains one or more radial ports 17 capable' of being made to register with one or more further ports 18 in the wall of the cylinder 1 provided for the discharge of spent gases of combustion. rlhe stationary sleeve 12 is open at both ends and also contains ports 12n which correspond with the exhaust ports 18 of the cylinder 1, the sleeve 2 operating between the cylinder 1 and the sleeve 12 while the piston 11 operates within the latter.

As Ithe sleeve 2 moves towards the crank i a spark plug or plugs 19 iitted to the cylinder 1 and adapted to ignite the charge through a port or ports 13 in said sleeve. The expansion of the fired charge between the closed end 2 of the sleeve 2 and the piston `11 then forces the former away from the crank shaft 1, and the piston towards said shaft.

rlravel of the sleeve 2 from the crank shaft l results in the charge last admitted to the chamber 16 being compressed between the head thereof, and the closed end 2"L of the sleeve 2, and upon the port or ports 13 in the latter registering with the inner end or ends of the transfer port or ports 141- in the cylinder wall, said last mentioned charge is transferred to the sleeve 2, and in passing thereinto assists in ejecting from the engine, the spent gases of the last. `tired charge, said spent gases being discharged per medium of the exhaust port or ports 18 in the cylinder 1, said port or ports 18 being opened by the registering therewith of the port or ports 17 in the sleeve 2,'simultaneously with the clearance of the port or ports 12A in the sleeve 12 by the piston 11 as the latter moves toward the crank shaft 4.

The ports 17 in the sleeve 2 are made wider than the ports 13, 14C or are positioned so that the exhaust ports 18 commence to open prior to the opening of the ports 14.

If desired the chamber 16 can be extended laterally or the interior thereof enlarged so that a cubic content may be obtained between the sleeve 2 and the head of said chamber 16 when the former is at the limit of the inward stroke equal to the cubic content between the closed end 2 of the sleeve 2 and the piston 11 when the former is at. the limit of its outward stroke and the latter at the limit of its inward stroke, lateral or side enlargement being preferred in order to avoid undue lengthening of the cylinder.

By virtue of the sliding vsleeve 2 being closed at its upper end 2 the sleeve acts as a compressor piston and a power piston alternately with the advantage that the heat dissipated from the top Iof the sleeve isabsorbed by the incoming charge during its initial compression in the chamber 16 and thus the vaporization of a low grade distillate is rendered complete.

The volume of gas induced into the coinpression chamber 16 is heated and compressed chamber 16 is preferably somewhat less than the greatest cubic content between the sleeve end 2 and the piston 11. By virtue of the opposed action of sleeve 2 and piston 11 the ratio of expansion of the spent gases is eX- actly twice as fast as a single piston engine running at the same R. P. M. This has the desired effect of increased eiiiciency at low engine speeds.

Owing to the opposing action of the piston 11 and sleeve 2 the products of combustion are expanded to twice the capacity of the compression chamber 16. The perfect balance ofthe engine is attained by the mechanically balanced reciprocating sleeve 2 and piston 11 moving in opposed directions.

ln the arrangement shown in Figures 7 and V8, the ports 13 in the head of the sliding sleeve 2 are dispensed with, enabling fewer piston rings to be used thereon, while the transfer port or ports 14 are continued down through the wall of the cylinder 1 and emerge through 'the interior surface by means of upwardly inclined portions 14 at a point just above the upper end of the stationary sleeve 12 while the sliding sleeve 2 contains inclined ports 2O approximately midway of its height.

In this form a charge of fuel induced into the chamber 16 by the downward stroke of the sleeve 2, receives its initial compression on the upward stroke of the latter and on the port or ports 2O in said sleeve 2, registering with the portion or portions 14 of the transfer ports 14, said charge is passed into the space between the head 2 of the sleeve 2, and the piston'11, in readiness for its final compression and ignition, by a plug 19, through a port 22 in said sleeve 2.

By forming the port or ports 20 in the sleeve 2 at a sharp upward angle as shown, a more complete scavenging effect is obtained.

By providing induction ports 21 in the cylinder 1 at the position indicated (dotted) in Figure 7, the admission of the fuel charge to the chamber 16 through a nonreturn valve at 15 is eliminated, and with ports 21 incorporated as mentioned the induction of the fuel charge is performed as follows:

The sliding sleeve 2 on its downward stroke creates a partial vacuum in the chamber 16 and as said sleeve is nearly at the bottom of its stroke or with the sleeve cranks approximately 30 degrees away from their bot- -tom centres, the head 2 of the sleeve 2, clears the induction port or ports 21, and allows a fuel charge to replace the partial vacuum in the chamber 16, the following return stroke Cil fof the sleeve 2 giving the charge so admitted its initial compression, and transferring it via the ports 14, 14n and 20 as before described to the space between the sleeve head 2a and the piston 1l.

The stationary sleeve l2 is provided with a base 22 containing slots 23 t-hrough which the connecting rods 5 of the sliding sleeve 2 operate, also when the stationary sleeve l2 is water jacketed, it is provided with inlets 24 which open into the larger .portions of the water space 25 between the lower ends of the pairs of vertical partitions 26 which extend right from the bottom of the water space 25, but not to the top thereof, so that the larger portions of the water space 25 between the pairs of partitions 26, communicate at their upper ends with the upper ends of the smaller portions of the water space 25, the lower ends of said smaller portions being connected with the water outlets 27.

lhat we do claim and desire to obtain by Letters Patent of the United States of America., is zl. In an internal combustion engine of the kind specified, a ported reciprocating sleeve, a piston, and a ported fixed sleeve between the latter and the reciprocating sleeve, a fuel compression chamber open to the engine cylinder, transfer ports from said chamber opening through the cylinder wall at a point just above the fixed sleeve, and induction ports in the engine cylinder between the lower ends of the transfer ports and the top of the cylinder, adapted to be opened to said chamber by downward movement of the reciprocating sleeve.

2. In an internal combustion engine, a cylinder and a fixed sleeve therein spaced from` the cylinder wall, a piston in said fixed sleeve and a recipocable sleeve having a closed inner end slidable between said cylinder and fixed sleeve, forming with said piston and the interior of said fixed sleeve a combustion chamber, means forming a compression chamber in controlled communication with a source of fuel mixture, communicating with said cylinder above said fixed sleeve, the reciprocable sleeve acting as a compression piston within said compression chamber, said cylinder and reciprocable sleeve being yprovided with transfer ports for establishing communication between said compression chamber and said combustion chamber, and said cylinder and said fixed and reciprocable sleeves being provided with exhaust ports for establishing communication between said combustion chamber and atmosphere, adjacent the lower limit of travel of said piston, said transfer and exhaust ports being arranged to register when the reciprocable sleeve and piston are respectively adjacent the upper and lower limits of their range of travel.

8. An internal combustion engine as claimed in claim 2, the exhaust ports being arranged to register in advance of the register ofthe transfer ports.

4. A n internal combustion engine as claimed in claim 2, the transfer ports opening into said combustion chamber just above the upper end of said fixed sleeve.

5. An internal combustion engine as claimed in claim 2, the transfer ports opening into the combustion chamber at an intermediate point and being inclined upwardly where they enter said combustion chamber. y 6. An internal combustion engine, a cylinder, a fixed open ended sleeve therein spaced from the cylinder wall.y a piston in said fixed sleeve and a reciprocable sleeve slidable between said cylinder and fixed sleeve, said fixed sleeve having a water space divided into compartments communicating with one another at the top, water inlet connections communicating with alternate compartments and water outlet connections communicating with the remaining alternate compartments.

7. An internal combustion engine as claimed in claim 2, means outside of said cylinder for operating said reciprocable sleeve, said cylinder being formed with longitudinal guiding slots for said operating means.

In testimony whereof we have signed our names to this specification.

GEORGE STANLEY EDLIN. HECTOR HALHEAD STEWART. 

